Each two-word phrase below can be anagrammed into two other words, which are related. Each of the anagrammed two-word phrases will in turn be related to each other.

1. UNLACE  NUT
2. SOUTH GARDEN
3. SHORTER TRIBES
4. HAT THEREFROM

HINT:
#1:The operative word is RELATED.
#2:The anagram for  UNLACE uses five of its six letters.

Answers:

1. UNCLE - AUNT
2. SON - DAUGHTER
3. BROTHER - SISTER
4. FATHER - MOTHER